Vector graphics are digital images expressed via a sequence of commands or mathematical statements, i.e., vector graphics statements, that place lines and shapes in a given two-dimensional or three-dimensional space. Compared to a simple bitmap, instead of containing a bit in the file for each bit of a line drawing, a vector graphic file describes a series of points to be connected. A vector image may be converted into a raster graphics image, which maps bits directly to a display space or a bitmap. The vector image may be converted to a raster image file prior to its display so that it can be ported between systems. Raster graphics are digital images created or captured as a set of samples of a given space. A raster is a grid of x and y coordinates on a display space. A raster image file identifies which of these coordinates to illuminate in monochrome or color values. The raster file is sometimes referred to as a bitmap because it contains information that is directly mapped to the display grid. A raster image processor (RIP) is a hardware device or a combination hardware/software device that converts images described in the form of vector graphics statements into raster graphics images or bitmaps that may be printed.
A printer description language (PDL), such as Postscript, PCL5, PCL XL (also called PCL6), comprises commands to render graphics produced by applications i.e., computer-readable instructions. In typical setups, the applications use the operating system (OS) graphics to display graphical items, and when the user requests a printout, the application gives similar OS graphics to a printer oriented display. The OS passes these graphics calls to a driver that translates them into a PDL. PCL XL is a page description language that is part of PCL languages and is similar to Microsoft's graphics device interface (GDI).
Extensible Markup Language (XML) is a general-purpose markup language for communicating structure data whereby users may define their own tags. XML Paper Specification (XPS) is a specification for a page description language and a fixed-document format. Printer Control Languages (PCL5 and PCL6) and XPS support graphic data expressed as vectors, text and contone, i.e., multi-level intensity, red-green-blue (RGB) and, in the case of XPS, contone cyan-magenta-yellow-black (CMYK). Other PDLs support other color spaces. The ink that may be used may include dilute colorants. For example, four-ink printing may be extended to six-ink printing, e.g., a light cyan (lt.cyan) and a light magenta (lt.magenta) may be added to four-ink printing: cyan-magenta-yellow-black-lt.cyan-lt.magenta-black. An exemplary form of seven-ink printing adds RGB to CMYK. Color dyes may be selected for strong, pure color as high-chroma primaries, such as orange and green. For example, the use of CMYK with PANTONE™ inks, and particularly PANTONE™ Hexachrome green and orange, may also provide for an alternative six-ink printing.
A bitmap defines a display space and color for each pixel. The colors may be defined in different spaces, such as RGB, CMYK, and LAB. Each color may be defined as some level in a range expressed by a level definable according to bit size, e.g., 1-bit, 2-bit, 8-bit, 16-bit, and 32-bit. The arrangement of the pixels may be planar, e.g., a grayscale-like planar scheme for each of red, green and blue planes, which can be combined to generate a multiple color bitmap. The arrangement of pixels may be interleaved, where, for example in a single array, each pixel contains information pertaining to the multiple colors of the arrangement, e.g., an R level value followed by a G level of value followed by a B level of value. For the contone CMYK, the planar arrangement may comprise four grayscale-like planes. The interleaved arrangement may have a pixel defined by four constituent levels, e.g., a C level value followed by a M level value, followed by a Y level value followed by a K level value.
A raster driver is a program that controls the raster firmware device of a printer. A raster driver converts the more general input/output instructions of the processing device to messages that the raster image processor may process and may apply color conversions and halftoning. A PCL5/XP RIP may not recognize processing graphics data already halftoned as rasterized by a raster external to the multifunction peripheral (MFP) device.